(a) Field of the Invention
This invention relates to an electroconductive thin film, particularly a polymerized thin film formed on a desired substrate by decomposing a specific metal complex starting material by glow discharge.
(b) Description of the Prior Art
Heretofore, most of electroconductive materials have relied on inorganic materials, but recently, organic materials, i.e. organic electroconductive materials have been getting popular, and researches and developments for them have been extensively made.
Typical examples of the organic conductive materials reported up to now are listed in the following Table 1.
TABLE 1 __________________________________________________________________________ Electric Conductivity Polymer Structure Dopant (s/cm) __________________________________________________________________________ polypyrrole (C.sub.4 H.sub.3 N)x BF.sub.4 10.sup.2 poly(N--methyl pyrrole) (C.sub.4 H.sub.2 NCH.sub.3)x poly(N--phenyl pyrrole) (C.sub.4 H.sub.2 NC.sub.6 H.sub.5)x poly(N--benzyl pyrrole) (C.sub.4 H.sub.2 NCH.sub.2 C.sub.6 H.sub.5)x (pyrrole)(N--methyl pyrrole) (C.sub.4 H.sub.3 N)x(C.sub.4 H.sub.2 NCH.sub.3)y BF.sub.4 5 .times. 10.sup.-3 .about.10.sup.2 copolymer (N--methyl pyrrole)(N--phenyl (C.sub.4 H.sub.2 NCH.sub.3)x(C.sub.4 H.sub.2 NC.sub.6 H.sub.5)y pyrrole) copolymer polyfuran (C.sub.4 H.sub.2 O)x BF.sub.4 10.sup.-5 poly thienylene (C.sub.4 H.sub.2 S)x BF.sub.4 1.3 .times. 10 poly(3-methyl-2,5-thienylene) (C.sub.4 HCH.sub.3 S)x poly(2,4-thienylene) (2,4-C.sub.4 H.sub.2 S)x iodine .sup. 7 .times. 10.sup.-11 (2,5-thienylene)(2,4- (2,5-C.sub.4 H.sub.2 S)x(2,4-C.sub.4 H.sub.2 S)y iodine 10.sup.-4 thienylene) copolymer [x/(x + y) = 0.87] poly(2,5-selenophene) (2,5-C.sub.4 H.sub.2 Se)x[x = 6.about.12] poly(p-phenylene) (p-C.sub.6 H.sub.4)x AsF.sub.5 5 .times. 10.sup.2 poly(m-phenylene) (m-C.sub.6 H.sub.4)x AsF.sub.5 10.sup.-3 poly(m-phenylene [m-C.sub.6 H.sub.2 (CONH.sub.2).sub.2 ]x TCNE .sup. 5 .times. 10.sup.-13 isophthalamide) poly(1,4-naphthylene) (1,4-C.sub.10 H.sub.6)x SbF.sub.5 1.1 .times. 10.sup.-4 poly(1,5-naphthylene) (1,5-C.sub.10 H.sub.6)x SbF.sub.5 1.5 .times. 10.sup.-5 poly(2,6-naphthylene) (2,6-C.sub.10 H.sub.6)x SbF.sub.5 1.8 .times. 10.sup.-1 poly(2,7-naphthylene) (2,7-C.sub.10 H.sub.6)x SbF.sub.5 1.7 .times. 10.sup.-3 hetero polyphenylene (Z--C.sub.10 H.sub.6 --C.sub.6 H.sub.4 --C.sub.10 H.sub.6)x AsF.sub.5 5 .times. 10.sup.-2 [z = O, x = 10] (C.sub.6 H.sub.4 ON--C.sub.6 H.sub.4 ON--C.sub.6 H.sub.4)x 6 AsF.sub.5 5 .times. 10.sup.-3 poly(p-phenylene oxide) (C.sub.6 H.sub.4 O)x AsF.sub.5 1.4 .times. 10.sup.-4 poly(diphenylene oxide) (C.sub.6 H.sub.4 C.sub.6 H.sub.4 O)x AsF.sub.5 1.1 .times. 10.sup.-5 poly acetylene (CH.dbd.CH)x AsF.sub.5 1.2 .times. 10.sup.3 __________________________________________________________________________
Among the above listed high molecular electroconductive materials, polymers such as polyacetylene, poly(p-phenylene), polypyrrole, polythienylene, polythiazole (SN)x, polyphthalocyanine and the like are considered to have relatively high electroconductivity and rectification properties. However, none of these materials are satisfactory in view of switching function and memory function.
A plasma-polymerized polystyrene (polymerized by glow discharge decomposition method) and the like have been reported to have good switching function and memory function (Journal of Applied Physics, Vol. 46, No. 8, August, 1975, U.S.A.). However, these polystyrene and the like have a disadvantage of being liable to cause dielectric breakdown. Poly-N-vinyl carbazole thin film has been reported in the same manner as above, but this has a disadvantage in that the time required for switching is too long, that is, it takes about several tenths of a second to several ten seconds (Journal of Chemical Society, Faraday Trans. 2, 72, 1911 (1976), U.S.A.).
As mentioned above, heretofore, there have been no organic type electroconductive high molecular thin films having both satisfactory switching and memory functions.